Here is a image from the game I am currently developing, 'Wolf'. It shows
off a few of the features of the rendering engine.

The landscape uses an adaptive quadtree both for storage and progressive
mesh rendering, with multitexturing to add detail and shadow maps. This
allows a massive area to be stored and effectively rendered. It also
supports wrapping to extend the terrain indefinately.

The sky is a series of domes, with the texture coordinates of cloud layers
distorted to appear flat. The cloud layers move across each other at
different speeds to give variety to the formations.

The geese, trees and footprints (that are just visible in the foreground)
are rendered using an adaptive quadtree which manages all the visibility,
level-of-detail and culling.

The geese themselves fly around using flocking rules to maintain their
formations. It's very cool just to follow them around, and they're easier
to take care of than real animals.

The image was captured on a Celeron 366 machine with a GeForce2 MX card
running under DirectX 8.